Dynamic ion radical sieve and ion radical aperture for an inductively coupled plasma (ICP) reactor

Abstract

Embodiments described herein provide apparatus and methods of etching a substrate using an ion etch chamber having a movable aperture. The ion etch chamber has a chamber body enclosing a processing region, a substrate support disposed in the processing region and having a substrate receiving surface, a plasma source disposed at a wall of the chamber body facing the substrate receiving surface, an ion-radical shield disposed between the plasma source and the substrate receiving surface, and a movable aperture member between the ion-radical shield and the substrate receiving surface. The movable aperture member is actuated by a lift assembly comprising a lift ring and lift supports from the lift ring to the aperture member. The ion-radical shield is supported by shield supports disposed through the aperture member. The aperture size, shape, and/or central axis location may be changed using inserts.

What is claimed is: 
     
       1. An ion etch chamber, comprising:
 a chamber body enclosing a processing region; 
 a substrate support disposed in the processing region and having a substrate receiving surface; 
 a plasma source disposed at a wall of the chamber body facing the substrate receiving surface; 
 an ion-radical shield disposed between the plasma source and the substrate receiving surface; and 
 a movable aperture member between the ion-radical shield and the substrate receiving surface, wherein the aperture member comprises an aperture plate having an aperture larger than the substrate receiving surface. 
 
     
     
       2. The ion etch chamber of  claim 1 , wherein the aperture member comprises an aperture plate and an edge shield extending toward the substrate receiving surface. 
     
     
       3. The ion etch chamber of  claim 2 , wherein the aperture plate has an aperture larger than the substrate receiving surface. 
     
     
       4. The ion etch chamber of  claim 2 , wherein the aperture member is coupled to a linear actuator operable to vary a distance between the aperture member and the substrate receiving surface. 
     
     
       5. The ion etch chamber of  claim 2 , wherein the aperture plate comprises quartz or ceramic. 
     
     
       6. The ion etch chamber of  claim 1 , wherein the aperture member is coupled to a linear actuator operable to vary a distance between the aperture member and the substrate receiving surface. 
     
     
       7. The ion etch chamber of  claim 1 , wherein the ion-radical shield is supported by a plurality of shield supports disposed through the aperture member. 
     
     
       8. The ion etch chamber of  claim 7 , wherein the aperture member is coupled to a linear actuator operable to vary a distance between the aperture member and the substrate receiving surface. 
     
     
       9. The ion etch chamber of  claim 8 , wherein a lift assembly is disposed between the aperture member and the linear actuator. 
     
     
       10. The ion etch chamber of  claim 9 , wherein the lift assembly comprises a lift ring and a plurality of lift supports on which the aperture member rests. 
     
     
       11. The ion etch chamber of  claim 10 , wherein the shield supports extend from a shield support ring disposed between the aperture member and the lift ring. 
     
     
       12. The ion etch chamber of  claim 11 , wherein the lift supports extend through the shield support ring. 
     
     
       13. A chamber for plasma processing of semiconductor substrates, comprising:
 a substrate support; 
 a plasma source opposite the substrate support; 
 an ion filter disposed between the plasma source and the substrate support; 
 a focus plate disposed between the ion filter and the substrate support, the focus plate coupled to a linear actuator, wherein the focus plate comprises a central aperture and a baffle extending from an edge portion of the focus plate toward the substrate support, and wherein the central aperture has a larger area than a substrate receiving surface of the substrate support; and 
 an actuator operable to control elevation of the focus plate. 
 
     
     
       14. The chamber of  claim 13 , wherein the focus plate is coupled to the linear actuator by a support ring and a plurality of supports extending from the support ring. 
     
     
       15. The chamber of  claim 14 , wherein the actuator has a stroke length sufficient to move the focus plate from a first position proximate the ion filter to a second position proximate the substrate support, wherein the baffle extends beyond the substrate receiving surface when the focus plate is in the second position. 
     
     
       16. A plasma etch apparatus, comprising:
 a chamber; 
 a plasma source disposed at one side of the chamber; 
 a substrate support disposed opposite the plasma source, with a stage facing the plasma source; 
 an ion-radical shield disposed between the plasma source and the substrate support, the ion-radical shield having a plurality of apertures formed in a region of the ion-radical shield aligned with the stage, the region of the ion-radical shield through which the apertures are formed having areal extent larger than the stage; and 
 an aperture plate disposed between the ion-radical shield and the substrate support, the aperture plate having a central aperture substantially the same size as the region of the ion-radical shield through which apertures are formed, wherein the aperture plate is coupled to a linear actuator by a lift ring and a plurality of lift supports extending from the lift ring and contacting the aperture plate.